/*
 *  linux/drivers/video/fbmem.c
 *
 *  Copyright (C) 1994 Martin Schaller
 *
 *      2001 - Documented with DocBook
 *      - Brad Douglas <brad@neruo.com>
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file COPYING in the main directory of this archive
 * for more details.
 */

#include <linux/console.h>
#include <linux/export.h>
#include <linux/fb.h>
#include <linux/fbcon.h>
#include <linux/lcd.h>
#include <linux/leds.h>

#include <video/nomodeset.h>

#include "fb_internal.h"

    /*
     *  Frame buffer device initialization and setup routines
     */

#define FBPIXMAPSIZE    (1024 * 8)

struct class *fb_class;

DEFINE_MUTEX(registration_lock);
struct fb_info *registered_fb[FB_MAX] __read_mostly;
int num_registered_fb __read_mostly;
#define for_each_registered_fb(i)               \
        for (i = 0; i < FB_MAX; i++)            \
                if (!registered_fb[i]) {} else

struct fb_info *get_fb_info(unsigned int idx)
{
        struct fb_info *fb_info;

        if (idx >= FB_MAX)
                return ERR_PTR(-ENODEV);

        mutex_lock(&registration_lock);
        fb_info = registered_fb[idx];
        if (fb_info)
                refcount_inc(&fb_info->count);
        mutex_unlock(&registration_lock);

        return fb_info;
}

void put_fb_info(struct fb_info *fb_info)
{
        if (!refcount_dec_and_test(&fb_info->count))
                return;
        if (fb_info->fbops->fb_destroy)
                fb_info->fbops->fb_destroy(fb_info);
}

/*
 * Helpers
 */

int fb_get_color_depth(struct fb_var_screeninfo *var,
                       struct fb_fix_screeninfo *fix)
{
        int depth = 0;

        if (fix->visual == FB_VISUAL_MONO01 ||
            fix->visual == FB_VISUAL_MONO10)
                depth = 1;
        else {
                if (var->green.length == var->blue.length &&
                    var->green.length == var->red.length &&
                    var->green.offset == var->blue.offset &&
                    var->green.offset == var->red.offset)
                        depth = var->green.length;
                else
                        depth = var->green.length + var->red.length +
                                var->blue.length;
        }

        return depth;
}
EXPORT_SYMBOL(fb_get_color_depth);

/*
 * Data padding functions.
 */
void fb_pad_aligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 s_pitch, u32 height)
{
        __fb_pad_aligned_buffer(dst, d_pitch, src, s_pitch, height);
}
EXPORT_SYMBOL(fb_pad_aligned_buffer);

void fb_pad_unaligned_buffer(u8 *dst, u32 d_pitch, u8 *src, u32 idx, u32 height,
                                u32 shift_high, u32 shift_low, u32 mod)
{
        u8 mask = (u8) (0xff << shift_high), tmp;
        int i, j;

        for (i = height; i--; ) {
                for (j = 0; j < idx; j++) {
                        tmp = dst[j];
                        tmp &= mask;
                        tmp |= *src >> shift_low;
                        dst[j] = tmp;
                        tmp = *src << shift_high;
                        dst[j+1] = tmp;
                        src++;
                }
                tmp = dst[idx];
                tmp &= mask;
                tmp |= *src >> shift_low;
                dst[idx] = tmp;
                if (shift_high < mod) {
                        tmp = *src << shift_high;
                        dst[idx+1] = tmp;
                }
                src++;
                dst += d_pitch;
        }
}
EXPORT_SYMBOL(fb_pad_unaligned_buffer);

/*
 * we need to lock this section since fb_cursor
 * may use fb_imageblit()
 */
char* fb_get_buffer_offset(struct fb_info *info, struct fb_pixmap *buf, u32 size)
{
        u32 align = buf->buf_align - 1, offset;
        char *addr = buf->addr;

        /* If IO mapped, we need to sync before access, no sharing of
         * the pixmap is done
         */
        if (buf->flags & FB_PIXMAP_IO) {
                if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
                        info->fbops->fb_sync(info);
                return addr;
        }

        /* See if we fit in the remaining pixmap space */
        offset = buf->offset + align;
        offset &= ~align;
        if (offset + size > buf->size) {
                /* We do not fit. In order to be able to re-use the buffer,
                 * we must ensure no asynchronous DMA'ing or whatever operation
                 * is in progress, we sync for that.
                 */
                if (info->fbops->fb_sync && (buf->flags & FB_PIXMAP_SYNC))
                        info->fbops->fb_sync(info);
                offset = 0;
        }
        buf->offset = offset + size;
        addr += offset;

        return addr;
}
EXPORT_SYMBOL(fb_get_buffer_offset);

int
fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var)
{
        struct fb_fix_screeninfo *fix = &info->fix;
        unsigned int yres = info->var.yres;
        int err = 0;

        if (var->yoffset > 0) {
                if (var->vmode & FB_VMODE_YWRAP) {
                        if (!fix->ywrapstep || (var->yoffset % fix->ywrapstep))
                                err = -EINVAL;
                        else
                                yres = 0;
                } else if (!fix->ypanstep || (var->yoffset % fix->ypanstep))
                        err = -EINVAL;
        }

        if (var->xoffset > 0 && (!fix->xpanstep ||
                                 (var->xoffset % fix->xpanstep)))
                err = -EINVAL;

        if (err || !info->fbops->fb_pan_display ||
            var->yoffset > info->var.yres_virtual - yres ||
            var->xoffset > info->var.xres_virtual - info->var.xres)
                return -EINVAL;

        if ((err = info->fbops->fb_pan_display(var, info)))
                return err;
        info->var.xoffset = var->xoffset;
        info->var.yoffset = var->yoffset;
        if (var->vmode & FB_VMODE_YWRAP)
                info->var.vmode |= FB_VMODE_YWRAP;
        else
                info->var.vmode &= ~FB_VMODE_YWRAP;
        return 0;
}
EXPORT_SYMBOL(fb_pan_display);

static int fb_check_caps(struct fb_info *info, struct fb_var_screeninfo *var,
                         u32 activate)
{
        struct fb_blit_caps caps, fbcaps;
        int err = 0;

        memset(&caps, 0, sizeof(caps));
        memset(&fbcaps, 0, sizeof(fbcaps));
        caps.flags = (activate & FB_ACTIVATE_ALL) ? 1 : 0;
        fbcon_get_requirement(info, &caps);
        info->fbops->fb_get_caps(info, &fbcaps, var);

        if (!bitmap_subset(caps.x, fbcaps.x, FB_MAX_BLIT_WIDTH) ||
            !bitmap_subset(caps.y, fbcaps.y, FB_MAX_BLIT_HEIGHT) ||
            (fbcaps.len < caps.len))
                err = -EINVAL;

        return err;
}

static void fb_lcd_notify_mode_change(struct fb_info *info,
                                      struct fb_videomode *mode)
{
        lcd_notify_mode_change_all(info->device, mode->xres, mode->yres);
}

int
fb_set_var(struct fb_info *info, struct fb_var_screeninfo *var)
{
        int ret = 0;
        u32 activate;
        struct fb_var_screeninfo old_var;
        struct fb_videomode mode;
        u32 unused;

        if (var->activate & FB_ACTIVATE_INV_MODE) {
                struct fb_videomode mode1, mode2;

                fb_var_to_videomode(&mode1, var);
                fb_var_to_videomode(&mode2, &info->var);
                /* make sure we don't delete the videomode of current var */
                ret = fb_mode_is_equal(&mode1, &mode2);
                if (!ret) {
                        ret = fbcon_mode_deleted(info, &mode1);
                        if (!ret)
                                fb_delete_videomode(&mode1, &info->modelist);
                }

                return ret ? -EINVAL : 0;
        }

        if (!(var->activate & FB_ACTIVATE_FORCE) &&
            !memcmp(&info->var, var, sizeof(struct fb_var_screeninfo)))
                return 0;

        activate = var->activate;

        /* When using FOURCC mode, make sure the red, green, blue and
         * transp fields are set to 0.
         */
        if ((info->fix.capabilities & FB_CAP_FOURCC) &&
            var->grayscale > 1) {
                if (var->red.offset     || var->green.offset    ||
                    var->blue.offset    || var->transp.offset   ||
                    var->red.length     || var->green.length    ||
                    var->blue.length    || var->transp.length   ||
                    var->red.msb_right  || var->green.msb_right ||
                    var->blue.msb_right || var->transp.msb_right)
                        return -EINVAL;
        }

        if (!info->fbops->fb_check_var) {
                *var = info->var;
                return 0;
        }

        /* bitfill_aligned() assumes that it's at least 8x8 */
        if (var->xres < 8 || var->yres < 8)
                return -EINVAL;

        /* Too huge resolution causes multiplication overflow. */
        if (check_mul_overflow(var->xres, var->yres, &unused) ||
            check_mul_overflow(var->xres_virtual, var->yres_virtual, &unused))
                return -EINVAL;

        ret = info->fbops->fb_check_var(var, info);

        if (ret)
                return ret;

        /* verify that virtual resolution >= physical resolution */
        if (var->xres_virtual < var->xres ||
            var->yres_virtual < var->yres) {
                pr_warn("WARNING: fbcon: Driver '%s' missed to adjust virtual screen size (%ux%u vs. %ux%u)\n",
                        info->fix.id,
                        var->xres_virtual, var->yres_virtual,
                        var->xres, var->yres);
                return -EINVAL;
        }

        if ((var->activate & FB_ACTIVATE_MASK) != FB_ACTIVATE_NOW)
                return 0;

        if (info->fbops->fb_get_caps) {
                ret = fb_check_caps(info, var, activate);

                if (ret)
                        return ret;
        }

        old_var = info->var;
        info->var = *var;

        if (info->fbops->fb_set_par) {
                ret = info->fbops->fb_set_par(info);

                if (ret) {
                        info->var = old_var;
                        printk(KERN_WARNING "detected "
                                "fb_set_par error, "
                                "error code: %d\n", ret);
                        return ret;
                }
        }

        fb_pan_display(info, &info->var);
        fb_set_cmap(&info->cmap, info);
        fb_var_to_videomode(&mode, &info->var);

        if (info->modelist.prev && info->modelist.next &&
            !list_empty(&info->modelist))
                ret = fb_add_videomode(&mode, &info->modelist);

        if (ret) {
                info->var = old_var;
                return ret;
        }

        fb_lcd_notify_mode_change(info, &mode);

        return 0;
}
EXPORT_SYMBOL(fb_set_var);

static void fb_lcd_notify_blank(struct fb_info *info)
{
        int power;

        switch (info->blank) {
        case FB_BLANK_UNBLANK:
                power = LCD_POWER_ON;
                break;
        /* deprecated; TODO: should become 'off' */
        case FB_BLANK_NORMAL:
                power = LCD_POWER_REDUCED;
                break;
        case FB_BLANK_VSYNC_SUSPEND:
                power = LCD_POWER_REDUCED_VSYNC_SUSPEND;
                break;
        /* 'off' */
        case FB_BLANK_HSYNC_SUSPEND:
        case FB_BLANK_POWERDOWN:
        default:
                power = LCD_POWER_OFF;
                break;
        }

        lcd_notify_blank_all(info->device, power);
}

static void fb_ledtrig_backlight_notify_blank(struct fb_info *info)
{
        if (info->blank == FB_BLANK_UNBLANK)
                ledtrig_backlight_blank(false);
        else
                ledtrig_backlight_blank(true);
}

int fb_blank(struct fb_info *info, int blank)
{
        int old_blank = info->blank;
        int ret;

        if (!info->fbops->fb_blank)
                return -EINVAL;

        if (blank > FB_BLANK_POWERDOWN)
                blank = FB_BLANK_POWERDOWN;

        info->blank = blank;

        ret = info->fbops->fb_blank(blank, info);
        if (ret)
                goto err;

        fb_bl_notify_blank(info, old_blank);
        fb_lcd_notify_blank(info);
        fb_ledtrig_backlight_notify_blank(info);

        return 0;

err:
        info->blank = old_blank;
        return ret;
}
EXPORT_SYMBOL(fb_blank);

static int fb_check_foreignness(struct fb_info *fi)
{
        const bool foreign_endian = fi->flags & FBINFO_FOREIGN_ENDIAN;

        fi->flags &= ~FBINFO_FOREIGN_ENDIAN;

#ifdef __BIG_ENDIAN
        fi->flags |= foreign_endian ? 0 : FBINFO_BE_MATH;
#else
        fi->flags |= foreign_endian ? FBINFO_BE_MATH : 0;
#endif /* __BIG_ENDIAN */

        if (fi->flags & FBINFO_BE_MATH && !fb_be_math(fi)) {
                pr_err("%s: enable CONFIG_FB_BIG_ENDIAN to "
                       "support this framebuffer\n", fi->fix.id);
                return -ENOSYS;
        } else if (!(fi->flags & FBINFO_BE_MATH) && fb_be_math(fi)) {
                pr_err("%s: enable CONFIG_FB_LITTLE_ENDIAN to "
                       "support this framebuffer\n", fi->fix.id);
                return -ENOSYS;
        }

        return 0;
}

static int do_register_framebuffer(struct fb_info *fb_info)
{
        int i, err = 0;
        struct fb_videomode mode;

        if (fb_check_foreignness(fb_info))
                return -ENOSYS;

        if (num_registered_fb == FB_MAX)
                return -ENXIO;

        for (i = 0 ; i < FB_MAX; i++)
                if (!registered_fb[i])
                        break;

        if (i >= FB_MAX)
                return -ENXIO;

        if (!fb_info->modelist.prev || !fb_info->modelist.next)
                INIT_LIST_HEAD(&fb_info->modelist);

        fb_var_to_videomode(&mode, &fb_info->var);
        err = fb_add_videomode(&mode, &fb_info->modelist);
        if (err < 0)
                return err;

        fb_info->node = i;
        refcount_set(&fb_info->count, 1);
        mutex_init(&fb_info->lock);
        mutex_init(&fb_info->mm_lock);

        /*
         * With an fb_blank callback present, we assume that the
         * display is blank, so that fb_blank() enables it on the
         * first modeset.
         */
        if (fb_info->fbops->fb_blank)
                fb_info->blank = FB_BLANK_POWERDOWN;

        fb_device_create(fb_info);

        if (fb_info->pixmap.addr == NULL) {
                fb_info->pixmap.addr = kmalloc(FBPIXMAPSIZE, GFP_KERNEL);
                if (fb_info->pixmap.addr) {
                        fb_info->pixmap.size = FBPIXMAPSIZE;
                        fb_info->pixmap.buf_align = 1;
                        fb_info->pixmap.scan_align = 1;
                        fb_info->pixmap.access_align = 32;
                        fb_info->pixmap.flags = FB_PIXMAP_DEFAULT;
                }
        }
        fb_info->pixmap.offset = 0;

        if (bitmap_empty(fb_info->pixmap.blit_x, FB_MAX_BLIT_WIDTH))
                bitmap_fill(fb_info->pixmap.blit_x, FB_MAX_BLIT_WIDTH);

        if (bitmap_empty(fb_info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT))
                bitmap_fill(fb_info->pixmap.blit_y, FB_MAX_BLIT_HEIGHT);

        if (fb_info->skip_vt_switch)
                pm_vt_switch_required(fb_info->device, false);
        else
                pm_vt_switch_required(fb_info->device, true);

        num_registered_fb++;
        registered_fb[i] = fb_info;

#ifdef CONFIG_GUMSTIX_AM200EPD
        {
                struct fb_event event;
                event.info = fb_info;
                fb_notifier_call_chain(FB_EVENT_FB_REGISTERED, &event);
        }
#endif

        return fbcon_fb_registered(fb_info);
}

static void unbind_console(struct fb_info *fb_info)
{
        int i = fb_info->node;

        if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
                return;

        fbcon_fb_unbind(fb_info);
}

static void unlink_framebuffer(struct fb_info *fb_info)
{
        int i;

        i = fb_info->node;
        if (WARN_ON(i < 0 || i >= FB_MAX || registered_fb[i] != fb_info))
                return;

        fb_device_destroy(fb_info);
        pm_vt_switch_unregister(fb_info->device);
        unbind_console(fb_info);
}

static void do_unregister_framebuffer(struct fb_info *fb_info)
{
        unlink_framebuffer(fb_info);
        if (fb_info->pixmap.addr &&
            (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) {
                kfree(fb_info->pixmap.addr);
                fb_info->pixmap.addr = NULL;
        }

        fbcon_delete_modelist(&fb_info->modelist);
        fb_destroy_modelist(&fb_info->modelist);
        registered_fb[fb_info->node] = NULL;
        num_registered_fb--;
#ifdef CONFIG_GUMSTIX_AM200EPD
        {
                struct fb_event event;
                event.info = fb_info;
                fb_notifier_call_chain(FB_EVENT_FB_UNREGISTERED, &event);
        }
#endif
        fbcon_fb_unregistered(fb_info);

        /* this may free fb info */
        put_fb_info(fb_info);
}

/**
 *      register_framebuffer - registers a frame buffer device
 *      @fb_info: frame buffer info structure
 *
 *      Registers a frame buffer device @fb_info.
 *
 *      Returns negative errno on error, or zero for success.
 *
 */
int
register_framebuffer(struct fb_info *fb_info)
{
        int ret;

        mutex_lock(&registration_lock);
        ret = do_register_framebuffer(fb_info);
        mutex_unlock(&registration_lock);

        return ret;
}
EXPORT_SYMBOL(register_framebuffer);

/**
 *      unregister_framebuffer - releases a frame buffer device
 *      @fb_info: frame buffer info structure
 *
 *      Unregisters a frame buffer device @fb_info.
 *
 *      Returns negative errno on error, or zero for success.
 *
 *      This function will also notify the framebuffer console
 *      to release the driver.
 *
 *      This is meant to be called within a driver's module_exit()
 *      function. If this is called outside module_exit(), ensure
 *      that the driver implements fb_open() and fb_release() to
 *      check that no processes are using the device.
 */
void
unregister_framebuffer(struct fb_info *fb_info)
{
        mutex_lock(&registration_lock);
        do_unregister_framebuffer(fb_info);
        mutex_unlock(&registration_lock);
}
EXPORT_SYMBOL(unregister_framebuffer);

static void devm_unregister_framebuffer(void *data)
{
        struct fb_info *info = data;

        unregister_framebuffer(info);
}

/**
 *      devm_register_framebuffer - resource-managed frame buffer device registration
 *      @dev: device the framebuffer belongs to
 *      @fb_info: frame buffer info structure
 *
 *      Registers a frame buffer device @fb_info to device @dev.
 *
 *      Returns negative errno on error, or zero for success.
 *
 */
int
devm_register_framebuffer(struct device *dev, struct fb_info *fb_info)
{
        int ret;

        ret = register_framebuffer(fb_info);
        if (ret)
                return ret;

        return devm_add_action_or_reset(dev, devm_unregister_framebuffer, fb_info);
}
EXPORT_SYMBOL(devm_register_framebuffer);

/**
 *      fb_set_suspend - low level driver signals suspend
 *      @info: framebuffer affected
 *      @state: 0 = resuming, !=0 = suspending
 *
 *      This is meant to be used by low level drivers to
 *      signal suspend/resume to the core & clients.
 *      It must be called with the console semaphore held
 */
void fb_set_suspend(struct fb_info *info, int state)
{
        WARN_CONSOLE_UNLOCKED();

        if (state) {
                fbcon_suspended(info);
                info->state = FBINFO_STATE_SUSPENDED;
        } else {
                info->state = FBINFO_STATE_RUNNING;
                fbcon_resumed(info);
        }
}
EXPORT_SYMBOL(fb_set_suspend);

static int __init fbmem_init(void)
{
        int ret;

        fb_class = class_create("graphics");
        if (IS_ERR(fb_class)) {
                ret = PTR_ERR(fb_class);
                pr_err("Unable to create fb class; errno = %d\n", ret);
                goto err_fb_class;
        }

        ret = fb_init_procfs();
        if (ret)
                goto err_class_destroy;

        ret = fb_register_chrdev();
        if (ret)
                goto err_fb_cleanup_procfs;

        fb_console_init();

        return 0;

err_fb_cleanup_procfs:
        fb_cleanup_procfs();
err_class_destroy:
        class_destroy(fb_class);
err_fb_class:
        fb_class = NULL;
        return ret;
}

#ifdef MODULE
static void __exit fbmem_exit(void)
{
        fb_console_exit();
        fb_unregister_chrdev();
        fb_cleanup_procfs();
        class_destroy(fb_class);
}

module_init(fbmem_init);
module_exit(fbmem_exit);
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("Framebuffer base");
#else
subsys_initcall(fbmem_init);
#endif

int fb_new_modelist(struct fb_info *info)
{
        struct fb_var_screeninfo var = info->var;
        struct list_head *pos, *n;
        struct fb_modelist *modelist;
        struct fb_videomode *m, mode;
        int err;

        list_for_each_safe(pos, n, &info->modelist) {
                modelist = list_entry(pos, struct fb_modelist, list);
                m = &modelist->mode;
                fb_videomode_to_var(&var, m);
                var.activate = FB_ACTIVATE_TEST;
                err = fb_set_var(info, &var);
                fb_var_to_videomode(&mode, &var);
                if (err || !fb_mode_is_equal(m, &mode)) {
                        list_del(pos);
                        kfree(pos);
                }
        }

        if (list_empty(&info->modelist))
                return 1;

        fbcon_new_modelist(info);

        return 0;
}

bool fb_modesetting_disabled(const char *drvname)
{
        bool fwonly = video_firmware_drivers_only();

        if (fwonly)
                pr_warn("Driver %s not loading because of nomodeset parameter\n",
                        drvname);

        return fwonly;
}
EXPORT_SYMBOL(fb_modesetting_disabled);

MODULE_LICENSE("GPL");